Systems and methods for multilayer peering

ABSTRACT

A software defined network, in accordance with some examples of the disclosure, may be used to optimizing traffic across a multi-layer inter-exchange for applications like automated private peering by incorporating packet switching along with OTN and/or optical switching into a converged system. Participants in private peering may have ports into the multi-layer inter-exchange, some to the L2 fabric which supports multi-tenant peering and some to the L1 or L0 fabric for higher-performance private peering.

FIELD OF DISCLOSURE

This disclosure relates generally to a communication network and morespecifically, but not exclusively, to multilayer peering in acommunication network.

BACKGROUND

Peering is a voluntary interconnection of separate networks/autonomoussystems (AS, that use separate routing tables within their network) forthe purpose of exchanging traffic between the users of each network. Anagreement by two or more networks to peer is instantiated by a physicalinterconnection of the networks and an exchange of routing informationthrough the Border Gateway Protocol (BGP) routing protocol (e.g. IETFRFC 4271). Peering involves two networks coming together to exchangetraffic with each other freely, and for mutual benefit. This ‘mutualbenefit’ is most often the motivation behind peering, which is oftendescribed solely by ‘reduced costs for transit services’.

The physical interconnections used for peering are categorized into twotypes: public peering—interconnection utilizing a multi-party sharedswitch fabric such as an Ethernet switch; and privatepeering—interconnection utilizing a point-to-point link between twoparties. Public peering is accomplished across a Layer 2 accesstechnology, generally called a shared fabric. These physicalinterconnections occur at a specific location where each carrier'sequipment is co-located with the other carriers. At these locations,multiple carriers interconnect with one or more other carriers across asingle physical port. Historically, public peering locations were knownas network access points (NAPs); today they are most often calledexchange points or Internet exchanges (“DO”). Many of the largestexchange points in the world can have hundreds of participants, and somespan multiple buildings and colocation facilities across a city.

Since public peering allows networks interested in peering tointerconnect with many other networks through a single port, it is oftenconsidered to offer “less capacity” than private peering, but to alarger number of networks. Many smaller networks, or networks which arejust beginning to peer, find that public peering exchange points providean excellent way to meet and interconnect with other networks which maybe open to peering with them. A few exchange points, particularly in theUnited States, are operated by commercial carrier-neutral third parties,which are critical for achieving cost-effective data centerconnectivity.

Private peering is the direct interconnection between only two networks,across a Layer 1 or 2 medium that offers dedicated capacity that is notshared by any other parties. Early in the history of the Internet, manyprivate peers occurred across ‘telco’ provisioned SONET circuits betweenindividual carrier-owned facilities. Today, most privateinterconnections occur at carrier hotels or carrier neutral colocationfacilities, where a direct cross connect can be provisioned betweenparticipants within the same building, usually for a much lower costthan telco circuits. Most of the traffic on the Internet, especiallytraffic between the largest networks, occurs via private peering.However, conventional approaches to both public and private peeringrequire the co-location of each carrier's network equipment.

Accordingly, there is a need for systems, apparatus, and methods thatimprove upon conventional approaches including the improved methods,system and apparatus provided hereby.

SUMMARY

The following presents a simplified summary relating to one or moreaspects and/or examples associated with the apparatus and methodsdisclosed herein. As such, the following summary should not beconsidered an extensive overview relating to all contemplated aspectsand/or examples, nor should the following summary be regarded toidentify key or critical elements relating to all contemplated aspectsand/or examples or to delineate the scope associated with any particularaspect and/or example. Accordingly, the following summary has the solepurpose to present certain concepts relating to one or more aspectsand/or examples relating to the apparatus and methods disclosed hereinin a simplified form to precede the detailed description presentedbelow.

In one aspect, a method for establishing a connection between first andsecond networks, the first and second networks being autonomous from oneanother and the method including: receiving a request for a connectionfrom a first network to a second network separate from the firstnetwork; coupling a first device of the first network to a second deviceof the second network remote from the first device; sending firstnetwork routing information from the first device to the second device;sending second network routing information from the second device to thefirst device; sending first data from the first device to the seconddevice using the second network routing information in a first format;and sending second data from the second device to the first device usingthe first network routing information in a second format.

In another aspect, an apparatus including: means for receiving a requestfor a connection from a first network to a second network separate fromthe first network; means for coupling a first device of the firstnetwork to a second device of the second network remote from the firstdevice; means for sending first network routing information from thefirst device to the second device; means for sending second networkrouting information from the second device to the first device; meansfor sending first data from the first device to the second device usingthe second network routing information in a first format; and means forsending second data from the second device to the first device using thefirst network routing information in a second format.

In still another aspect, a non-transient computer readable mediumcontaining program instructions for causing a processor to perform aprocess including: receiving a request for a connection from a firstnetwork to a second network separate from the first network; coupling afirst device of the first network to a second device of the secondnetwork remote from the first device; sending first network routinginformation from the first device to the second device; sending secondnetwork routing information from the second device to the first device;sending first data from the first device to the second device using thesecond network routing information in a first format; and sending seconddata from the second device to the first device using the first networkrouting information in a second format.

Other features and advantages associated with the apparatus and methodsdisclosed herein will be apparent to those skilled in the art based onthe accompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of aspects of the disclosure and many ofthe attendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingswhich are presented solely for illustration and not limitation of thedisclosure, and in which:

FIG. 1 illustrates an exemplary local and remote peering via a packetand optical system in accordance with some examples of the disclosure.

FIG. 2 illustrates an exemplary local and remote peering via a packetand optical network fabrics in accordance with some examples of thedisclosure.

FIG. 3 illustrates an exemplary local and remote peering via a singleinterface in accordance with some examples of the disclosure.

In accordance with common practice, the features depicted by thedrawings may not be drawn to scale. Accordingly, the dimensions of thedepicted features may be arbitrarily expanded or reduced for clarity. Inaccordance with common practice, some of the drawings are simplified forclarity. Thus, the drawings may not depict all components of aparticular apparatus or method. Further, like reference numerals denotelike features throughout the specification and figures.

DETAILED DESCRIPTION

The exemplary methods, apparatus, and systems disclosed hereinadvantageously address the industry needs, as well as other previouslyunidentified needs, and mitigate shortcomings of the conventionalmethods, apparatus, and systems. New methods and systems are describedherein for distributing the ports and functions of a peeringinter-exchange as well as techniques to optimize the trafficdistribution between layer 2 packet switching and layer 1 or 0 foroptical switching based on a number of variable factors such as trafficvolume, service level agreements between network carriers, time based,etc. Unlike conventional inter-exchanges that require a network devicefrom each network to be connected to be located in the same geographiclocation so that each device can be physically directly connected to theother device, this new and improved systems and methods allow thedevices to be remote from each other without a direct fiber connectionbetween them. In addition, the conventional inter-exchanges only allow alayer 2 to layer 2 connection or layer 0/1 to layer 0/1 connection whilethe improved systems and methods allow a layer 2 to a layer 0/1connection and dynamically switching between connection types to satisfyservice rules or optimize traffic flows.

FIG. 1 illustrates an exemplary local and remote peering via a packetand optical system in accordance with some examples of the disclosure.As shown in FIG. 1, a plurality of independent or autonomous systems(AS) or networks such as a first network 110, a second network 120, athird network 130, and a fourth network 140. While only four networksare shown, it should be understood that more or less may be includeddepending on the extent of the peering arrangement. Each AS or network110-140 has its own unique Internet Protocol (IP) addressing and BorderGateway Protocol (BGP) routing. BGP is a standardized exterior gatewayprotocol designed to exchange routing and reachability information amongAS on the Internet. The protocol is often classified as a path vectorprotocol but is sometimes also classed as a distance-vector routingprotocol. The Border Gateway Protocol makes routing decisions based onpaths, network policies, or rule-sets configured by a networkadministrator and is involved in making core routing decisions. BGP maybe used for routing within an autonomous system.

BGP neighbors, called peers, are established by manual configurationbetween routers or switches to create a TCP session on port 179. A BGPspeaker sends 19-byte keep-alive messages every 60 seconds to maintainthe connection. When BGP runs between two peers in the same autonomoussystem (AS), it is referred to as Internal BGP (iBGP or Interior BorderGateway Protocol). When it runs between different autonomous systems, itis called External BGP (EBGP or Exterior Border Gateway Protocol).Routers on the boundary of one AS exchanging information with another ASare called border or edge routers or simply eBGP peers and are typicallyconnected directly. Filtering routes learned from peers, theirtransformation before redistribution to peers or before plumbing theminto the routing table is typically controlled via route-maps mechanism.These are basically rules which allow applying certain actions to routesmatching certain criteria on either ingress or egress path. These rulescan specify that the route is to be dropped or, alternatively, itsattributes are to be modified. It is usually the responsibility of theAS administrator to provide the desired route-map configuration on arouter supporting BGP.

As shown in FIG. 1, a first network 110 may include a first networkdevice 111 (e.g. a switch or router) with a layer 2 port 112 and a layer0/1 port 113, and a second network device 114 with a layer 2 port 115and a layer 0/1 port 116. A second network 120 may include a thirdnetwork device 121 with a layer 2 port 122 and a layer 0/1 port 123, afourth network device 124 with a layer 2 port 125 and a layer 0/1 port126, and a fifth network device 127 with a layer 2 port 128 and a layer0/1 port 129. A third network 130 may include a sixth network device 131with a layer 2 port 132 and a layer 0/1 port 133 that are connected toanother device (e.g. border gateway, switch, router, etc.) not shownthat includes an associated layer 2 port 134 and an associated layer 0/1port 135. The associated ports 134 and 135 may be located in anotherdevice that is part of the third network 130 or the sixth network device131. A fourth network 140 may include a seventh network device 141 andan eighth network device 142 with an packet optical transport networkport 143 (e.g. a P-OTN device) that includes converged layer 0/1/2/3switching and routing along with an associated layer 0/1 port 144. Asshown, for example, a peering may be set up between the first network110 (content provider) and the fourth network 140 (access networkprovider). In this example, a data flow may start as L2 packet flow fromthe first network device 111 to the L2 port 112 and then converted tothe L0/1 port 144, and from the L0/1 port 144 as an optical signal (e.g.a L2 packet encapsulated in a L0/1 OTN wrapper) to the fourth network140. The conversion from a L2 packet switched by an L2 switch fabric toan OTN signal switched by a L0/1 fabric may take place in the firstnetwork device 111 or any network device along the path from device 111to a recipient within the fourth network 140.

By implementing a software defined network (SDN) approach in combinationwith peering connections, a distributed a multi-layer inter-exchange(MLIX) 100 may be created that allows for optimization of applicationslike automated private peering. This allows the MLIX 100 to incorporatepacket switching along with OTN and/or optical switching into aconverged system. Thus, participants in private peering will have portsinto the MLIX 100, some to the L2 fabric which supports multi-tenantpeering, some to the L1 or L0 fabric for higher-performance privatepeering. While FIG. 1 is drawn to simulate a single device, the MLIX 100may be composed of ports from various network devices in each of theparticipating peering networks or AS. Thus, the network is effectivelyused as a switch fabric instead of the internal switch fabric of asingle network element, such as an L3 router. This will allow multipledifferent ways to interconnect a content provider (AS peeringparticipant) router to the L2/L1/L0 fabric of multiple devices (or asingle device). For example, L2 to L1 to L0 or L2 direct to LO withoutwasting OTN switching bandwidth. This configuration also allows separateL1 and L0 fabrics to be used. In addition, it is no longer necessary forco-location of an L3 router (e.g. BGP router server) at the internetexchange site for multilateral interconnections. Multilateralinterconnection is a method of exchanging routing information betweenthree or more exterior BGP speakers using a single intermediate brokersystem, referred to as a route server. Route servers are typically usedon shared access media networks, such as Internet exchange points(IXPs), to facilitate simplified interconnection between multipleInternet routers. Instead, an expensive L3 router can be situated at aremote site and the router may have an OTN or other cheaper interconnectto the IX site.

FIG. 2 illustrates an exemplary local and remote peering via a packetand optical network fabrics in accordance with some examples of thedisclosure. This may allow leveraging of SDN-based intelligence andanalytics to assess current traffic flow through an MLIX and balancetraffic across the MLIX for optimum performance. For example, algorithmsin a SDN MLIX Optimizer may determine which large flows to offload fromthe L2 peering fabric to the L1/L0 fabric, based on flow size, duration,variance, source and/or destination, and other attributes includingeconomic policies between peering participants. It may also allowleveraging SDN control over traffic source and MLIX participantsinterconnected to the MLIX as well as the MLIX through control over thepacket fabric, creating virtual switches that each AS can control, andusing a route server within the MLIX controller for BGP sessionmanagement.

As shown in FIG. 2, a first network 210 may include a first networkdevice 211 (e.g. a switch or router) with a layer 2 port 212 and a layer0/1 port 213, and a second network device 214 with a layer 2 port 215and a layer 0/1 port 216. A second network 220 may include a thirdnetwork device 221 with a layer 2 port 222 and a layer 0/1 port 223, afourth network device 224 with a layer 2 port 225 and a layer 0/1 port226, and a fifth network device 227 with a layer 2 port 228 and a layer0/1 port 229. A third network 230 may include a sixth network device 231with a layer 2 port 232 and a layer 0/1 port 233 that are connected toanother device (e.g. border gateway, switch, router, etc.) not shownthat includes an associated layer 2 port 234 and an associated layer 0/1port 235. The associated ports 234 and 235 may be located in anotherdevice that is part of the third network 230 or the sixth network device231. A fourth network 240 may include a seventh network device 241 andan eighth network device 242 with an packet optical transport networkport 243 (e.g. a P-OTN device) that includes converged layer 0/1/2/3switching and routing along with an associated layer 0/1 port 244. Asshown, for example, a peering may be set up between the first network210 (content provider) and the fourth network 240 (access networkprovider). In this example, a data flow may start as L2 packet flow fromthe fourth network device 214 to the L2 port 215 and then converted tothe L0/1 port 244, and from the L0/1 port 244 as an optical signal (e.g.a L2 packet encapsulated in a L0/1 OTN wrapper) to the fourth network240. The conversion from a L2 packet switched by an L2 switch fabric toan OTN signal switched by a L0/1 fabric may take place in the fourthnetwork device 214 or any network device along the path from device 214to a recipient within the fourth network 240.

FIG. 3 illustrates an exemplary local and remote peering via a singleinterface in accordance with some examples of the disclosure. Optimizingthe traffic flow is accomplished in various ways. By analyzing flowsbetween a source and MLIX participants, a SDN MLIX Optimizer candynamically steer flows to transit the appropriate layer of the MLIX.For transit of peering traffic across circuit-switched access networks(e.g. remote peering), packet traffic may be encapsulated over OTN intothe access network. Different attributes and parameters may beconsidered for optimization of traffic through an MLIX—(1) loadbalancing traffic across an MLIX (centralized or distributed); (2)metrics other than destination address/prefix/AS path to performoptimization and may include other L4-L7 attributes (application-awaretraffic routing within MLIX); (3) cost optimization between differentnetwork layers based on flow sizes, time-of-day, cost of transit,maximum fit of traffic for maximum traffic/revenue generation, or otherheuristics; (4) design for failure resiliency (e.g., single point offailure within MLIX); (5) latency; (6) other Traffic Engineering (TE)parameters; and (7) traffic routing through an MLIX based on thevisibility of bandwidth utilization, oversubscription, burst size, andother potential policies.

As shown in FIG. 3, a first network 310 may include a first networkdevice 311 (e.g. a switch or router) with a layer 2 port 312, and asecond network device 314 with a layer 2 port 315. A second network 320may include a third network device 321 with a layer 2 port 322, a fourthnetwork device 324 with a layer 2 port 325. A third network 330 mayinclude a sixth network device 331 with a layer 2 port 332 that areconnected to another device (e.g. border gateway, switch, router, etc.)not shown that includes an associated layer 2 port 334. The associatedport 334 may be located in another device that is part of the thirdnetwork 330 or the sixth network device 331. A fourth network 340 mayinclude a seventh network device 341 and an eighth network device 342with an packet optical transport network port 343 (e.g. a P-OTN device)that includes converged layer 0/1/2/3 switching and routing along withan associated layer 2 port 328. As shown, for example, a peering may beset up between the first network 310 (content provider) and the secondnetwork 320 (access network provider). In this example, a data flow maystart as L2 packet flow from the first network device 311 to the L2 port212 and then converted to a L0/1 data flow temporarily then back to apacket flow before the L2 port 322, and from the L2 port 322 as a packetsignal (e.g. a L2 packet) to the second network 220. The conversion froma L2 packet switched by an L2 switch fabric to an OTN signal switched bya L0/1 fabric may take place in the first network device 311 or anynetwork device along the path from device 311 to the recipient the thirddevice 321 within the second network 220.

Examples of devices that may use the methods and systems describedherein may include routers or switches, such as Infinera's DTN-Xplatform, that may have multiple functionalities like L0 wavelengthdivision multiplexing (WDM) transport capabilities, L1 digital OTNswitching capabilities, and L2 packet switching capabilities. Thenetwork may be optimized by enabling the packet switching feature innetwork devices using protocols such as MPLS-TP and switching LSP's, andpacket switching in the network core can be performed by the devices.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any details described herein as “exemplary”is not necessarily to be construed as preferred or advantageous overother examples. Likewise, the term “examples” does not require that allexamples include the discussed feature, advantage or mode of operation.Use of the terms “in one example,” “an example,” “in one feature,”and/or “a feature” in this specification does not necessarily refer tothe same feature and/or example. Furthermore, a particular featureand/or structure can be combined with one or more other features and/orstructures. Moreover, at least a portion of the apparatus describedhereby can be configured to perform at least a portion of a methoddescribed hereby.

The terminology used herein is for the purpose of describing particularexamples only and is not intended to be limiting of examples of thedisclosure. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises”, “comprising,” “includes,” and/or “including,” when usedherein, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

It should be noted that the terms “connected,” “coupled,” or any variantthereof, mean any connection or coupling, either direct or indirect,between elements, and can encompass a presence of an intermediateelement between two elements that are “connected” or “coupled” togethervia the intermediate element.

Any reference herein to an element using a designation such as “first,”“second,” and so forth does not limit the quantity and/or order of thoseelements. Rather, these designations are used as a convenient method ofdistinguishing between two or more elements and/or instances of anelement. Thus, a reference to first and second elements does not meanthat only two elements can be employed, or that the first element mustnecessarily precede the second element. Also, unless stated otherwise, aset of elements can comprise one or more elements.

Further, many examples are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, these sequence ofactions described herein can be considered to be embodied entirelywithin any form of computer readable storage medium having storedtherein a corresponding set of computer instructions that upon executionwould cause an associated processor to perform the functionalitydescribed herein. Thus, the various aspects of the disclosure may beembodied in a number of different forms, all of which have beencontemplated to be within the scope of the claimed subject matter. Inaddition, for each of the examples described herein, the correspondingform of any such examples may be described herein as, for example,“logic configured to” perform the described action.

Nothing stated or illustrated depicted in this application is intendedto dedicate any component, step, feature, benefit, advantage, orequivalent to the public, regardless of whether the component, step,feature, benefit, advantage, or the equivalent is recited in the claims.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the examples disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The methods, sequences and/or algorithms described in connection withthe examples disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration).

Although some aspects have been described in connection with a device,it goes without saying that these aspects also constitute a descriptionof the corresponding method, and so a block or a component of a deviceshould also be understood as a corresponding method step or as a featureof a method step. Analogously thereto, aspects described in connectionwith or as a method step also constitute a description of acorresponding block or detail or feature of a corresponding device. Someor all of the method steps can be performed by a hardware apparatus (orusing a hardware apparatus), such as, for example, a microprocessor, aprogrammable computer or an electronic circuit. In some examples, someor a plurality of the most important method steps can be performed bysuch an apparatus.

In the detailed description above it can be seen that different featuresare grouped together in examples. This manner of disclosure should notbe understood as an intention that the claimed examples require morefeatures than are explicitly mentioned in the respective claim. Rather,the situation is such that inventive content may reside in fewer thanall features of an individual example disclosed. Therefore, thefollowing claims should hereby be deemed to be incorporated in thedescription, wherein each claim by itself can stand as a separateexample. Although each claim by itself can stand as a separate example,it should be noted that-although a dependent claim can refer in theclaims to a specific combination with one or a plurality of claims-otherexamples can also encompass or include a combination of said dependentclaim with the subject matter of any other dependent claim or acombination of any feature with other dependent and independent claims.Such combinations are proposed herein, unless it is explicitly expressedthat a specific combination is not intended. Furthermore, it is alsointended that features of a claim can be included in any otherindependent claim, even if said claim is not directly dependent on theindependent claim.

It should furthermore be noted that methods disclosed in the descriptionor in the claims can be implemented by a device comprising means forperforming the respective steps or actions of this method.

Furthermore, in some examples, an individual step/action can besubdivided into a plurality of sub-steps or contain a plurality ofsub-steps. Such sub-steps can be contained in the disclosure of theindividual step and be part of the disclosure of the individual step.

While the foregoing disclosure shows illustrative examples of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the examples of the disclosuredescribed herein need not be performed in any particular order.Additionally, well-known elements will not be described in detail or maybe omitted so as to not obscure the relevant details of the aspects andexamples disclosed herein. Furthermore, although elements of thedisclosure may be described or claimed in the singular, the plural iscontemplated unless limitation to the singular is explicitly stated.

What is claimed is:
 1. A method for establishing a connection betweenfirst and second networks, the first and second networks beingautonomous from one another; the method comprising: receiving a requestfor a connection from the first network to the second network separatefrom the first network; coupling a first device of the first network toa second device of the second network remote from the first device;sending first network routing information from the first device to thesecond device; sending second network routing information from thesecond device to the first device; sending first data from the firstdevice to the second device using the second network routing informationin a first format; and sending second data from the second device to thefirst device using the first network routing information in a secondformat.
 2. The method of claim 1, further comprising: converting thefirst data from the first format to the second format; and receiving thefirst data at the second device in the second format.
 3. The method ofclaim 1, further comprising: converting the second data from the secondformat to the first format; and receiving the second data at the firstdevice in the first format.
 4. The method of claim 1, furthercomprising: converting the first data from the first format to thesecond format; transmitting the first data in the second format;converting the first data from the second format to the first format;and receiving the first data at the second device in the first format.5. The method of claim 1, wherein the first format is a packet format.6. The method of claim 1, wherein the second format is an opticaltransport network format.
 7. The method of claim 1, wherein the firstformat is a packet format and the second format is an optical transportnetwork format.
 8. The method of claim 1, wherein the first format andthe second format are the same.
 9. The method of claim 1, wherein thefirst format and the second format are different.
 10. An apparatuscomprising: means for receiving a request for a connection from a firstnetwork to a second network separate from the first network; means forcoupling a first device of the first network to a second device of thesecond network remote from the first device; means for sending firstnetwork routing information from the first device to the second device;means for sending second network routing information from the seconddevice to the first device; means for sending first data from the firstdevice to the second device using the second network routing informationin a first format; and means for sending second data from the seconddevice to the first device using the first network routing informationin a second format.
 11. The apparatus of claim 10, further comprising:means for converting the first data from the first format to the secondformat; and means for receiving the first data at the second device inthe second format.
 12. The apparatus of claim 10, further comprising:means for converting the second data from the second format to the firstformat; and means for receiving the second data at the first device inthe first format.
 13. The apparatus of claim 10, further comprising:means for converting the first data from the first format to the secondformat; means for transmitting the first data in the second format;means for converting the first data from the second format to the firstformat; and means for receiving the first data at the second device inthe first format.
 14. The apparatus of claim 10, wherein the firstformat is a packet format.
 15. apparatus of claim 10, wherein the secondformat is an optical transport network format.
 16. The apparatus ofclaim 10, wherein the first format is a packet format and the secondformat is an optical transport network format.
 17. The apparatus ofclaim 10, wherein the first format and the second format are the same.18. The apparatus of claim 10, wherein the first format and the secondformat are different.
 19. A method for establishing a peering connectionbetween first and second networks, the first and second networks beingautonomous from one another; the method comprising: connecting the firstnetwork to a first device; connecting the second network to the firstdevice; receiving first network routing information at the first device;receiving second network routing information at the first device;receiving first data from the first network at the first device, thefirst data being in a layer 2 format; converting the first data from thelayer 2 format to a layer 1 format or a layer 0 format; and sending thefirst data to the second network in the layer 1 format or the layer 0format using the second network routing information.
 20. The method ofclaim 19, wherein the first device is one of an Ethernet switch or afirst router and a second router, the first router configured to routethe first data using the first network routing information and thesecond router configured to route the first data using the secondnetwork routing information.